AMNIOTIC-FLUID ERYTHROPOIETIN LEVELS IN NORMAL AND DOWNS-SYNDROME PREGNANCIES

The aim of this study was to measure the levels of erythropoietin in a mniotic fluid from normal and trisomy 21 pregnancies at 10 to 20 weeks gestation. Samples of amniotic fluid were collected from 142 women wi th singleton pregnancies after genetic amniocentesis; 110 had a normal fetal karyotype and 32 had trisomy 21. Erythropoietin was measured us ing a double antibody radioimmunoassay. Amniotic fluid erythropoietin levels in normal pregnancies increased from 10 weeks (mean 3.2 mU/ml; range < 2.0-6.3 mU/ml) to 20 weeks gestation (mean 7.9 mU/ml; range 2. 0-11.5 mU/ml). There was a significant linear correlation between gest ational age and erythropoietin level (r = 0.543; P < 0.0001). For the 32 patients with trisomy 21 pregnancies the median multiple of the med ian (MoM) was 1.11 (range 0.42-2.1). There was no difference between e rythropoietin levels in amniotic fluid from normal and Down's syndrome pregnancies (U = 2352, P = 0.75, 95% CI = -0.11, 0.18); (Mann-Whitney U-test).